Add AudioPlayQueue

Audio.h

 #include "output_i2s.h"
 #include "output_pwm.h"
 #include "play_memory.h"
+#include "play_queue.h"
 #include "play_sd_raw.h"
 #include "play_sd_wav.h"
 #include "synth_tonesweep.h"

play_queue.cpp

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "play_queue.h"
+#include "utility/dspinst.h"
+
+
+int16_t * AudioPlayQueue::getBuffer(void)
+{
+	while (1) {
+		userblock = allocate();
+		if (userblock) return userblock->data;
+		yield();
+	}
+}
+
+void AudioPlayQueue::playBuffer(void)
+{
+	uint32_t h;
+
+	if (!userblock) return;
+	h = head + 1;
+	if (h >= 32) h = 0;
+	while (tail == h) ; // wait until space in the queue
+	queue[h] = userblock;
+	head = h;
+	userblock = NULL;
+}
+
+void AudioPlayQueue::update(void)
+{
+	audio_block_t *block;
+	uint32_t t;
+
+	t = tail;
+	if (t != head) {
+		if (++t >= 32) t = 0;
+		block = queue[t];
+		tail = t;
+		transmit(block);
+		release(block);
+	}
+}
+

play_queue.h

+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef play_queue_h_
+#define play_queue_h_
+
+#include "AudioStream.h"
+
+class AudioPlayQueue : public AudioStream
+{
+public:
+	AudioPlayQueue(void) : AudioStream(0, NULL),
+		userblock(NULL), head(0), tail(0) { }
+	void play(int16_t data);
+	void play(const int16_t *data, uint32_t len);
+	int16_t * getBuffer(void);
+	void playBuffer(void);
+	void stop(void);
+	//bool isPlaying(void) { return playing; }
+	virtual void update(void);
+private:
+	audio_block_t *queue[32];
+	audio_block_t *userblock;
+	volatile uint8_t head, tail;
+};
+
+#endif